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51.
A series of pot experiments and field trials were carried out to evaluate the effects of arbuscular mycorrhizal fungi (AMF) on activities of soil enzymes and carbon sequestration capacity in reclaimed mine soil. A complex substrate of coal gangue, fly ash and sludge was used as reclaimed mine soil, and ryegrass was planted with AMF inoculation to construct a plant-complex substrate-microbe ecological restoration system. The changes to the soil organic carbon (SOC), activities of soil enzymes and glomalin-related soil protein (GRSP) were measured and the effects of AMF on activities of soil enzymes and carbon sequestration capacity in reclaimed mine soil were analyzed. The results show that the contents of GRSP (total glomalin (TG) and easily extractable glomalin (EEG)), SOC and activities of enzymes increased, and the increments were higher in the AMF inoculation treated plant-complex substrate-microbe ecological restoration systems than those with no AMF inoculated treatments after 12 months of ryegrass growth. TG, EEG and soil enzyme activity have a significant positive correlation, and the correlative coefficient was 0.427–0.573; SOC and TG, EEG have a significant positive correlation (p < 0.01), indicating that AMF plays an important role in carbon sequestration of reclaimed mine soils. 相似文献
52.
A Radiating Gradient Vector Flow (RGVF) Snake aiming at accurate extraction of both the nucleus and cytoplasm from a single-cell cervical smear image is proposed. After preprocessing, the areas in the image are roughly clustered into nucleus, cytoplasm and the background by a spatial K-means clustering algorithm. After initial contours are extracted, the image is segmented using RGVF. RGVF involves a new edge map computation method and a stack-based refinement, and is thus robust to contaminations and can effectively locate the obscure boundaries. The boundaries can also be correctly traced even if there are interferences near the cytoplasm and nucleus regions. Experiments performed on the Herlev dataset, which contains 917 images show the effectiveness of the proposed algorithm. 相似文献
53.
This paper presents a novel ranking framework for content-based multimedia information retrieval (CBMIR). The framework introduces relevance features and a new ranking scheme. Each relevance feature measures the relevance of an instance with respect to a profile of the targeted multimedia database. We show that the task of CBMIR can be done more effectively using the relevance features than the original features. Furthermore, additional performance gain is achieved by incorporating our new ranking scheme which modifies instance rankings based on the weighted average of relevance feature values. Experiments on image and music databases validate the efficacy and efficiency of the proposed framework. 相似文献
54.
Pan JJ Pan SJ Yin J Ni LM Yang Q 《IEEE transactions on pattern analysis and machine intelligence》2012,34(3):587-600
Recent years have witnessed the growing popularity of sensor and sensor-network technologies, supporting important practical applications. One of the fundamental issues is how to accurately locate a user with few labeled data in a wireless sensor network, where a major difficulty arises from the need to label large quantities of user location data, which in turn requires knowledge about the locations of signal transmitters or access points. To solve this problem, we have developed a novel machine learning-based approach that combines collaborative filtering with graph-based semi-supervised learning to learn both mobile users' locations and the locations of access points. Our framework exploits both labeled and unlabeled data from mobile devices and access points. In our two-phase solution, we first build a manifold-based model from a batch of labeled and unlabeled data in an offline training phase and then use a weighted k-nearest-neighbor method to localize a mobile client in an online localization phase. We extend the two-phase colocalization to an online and incremental model that can deal with labeled and unlabeled data that come sequentially and adapt to environmental changes. Finally, we embed an action model to the framework such that additional kinds of sensor signals can be utilized to further boost the performance of mobile tracking. Compared to other state-of-the-art systems, our framework has been shown to be more accurate while requiring less calibration effort in our experiments performed on three different testbeds. 相似文献
55.
This paper presents an integration technology for RF passives using benzocyclobutene (BCB)/metal multilayer interconnection
for system-in-package applications. This technology has been specially developed for RF subsystem packages in which a thick
polymer, BCB (more than 15 μm thick), is adopted as dielectric with lossy silicon as substrate for its excellent characteristics.
Both dry-etch BCB and photosensitive BCB are applied in this work, and their processes are briefly introduced and compared.
An RF power divider, an MIM capacitor, different types of RF inductors as well as a coupled microstrip based band-pass filter
are fabricated and measured at wafer level. The results show good electrical performances, and accordingly the passives are
well applicable in RF band. Moreover, the subsystem models including monolithic chips connected with passives are presented. 相似文献
56.
针对碎片化趋势下的奥运会商业模式,社交网络发布的有关奥运会新闻的传播与接收问题,综合分析一个社交网络专业推广者与普通网络用户平均每天的新增粉丝数,粉丝再把自己获得的信息分享给自己粉丝的情况,再借助Excel、Access软件分析并统计附件中社交网站用户之间的连接关系数据,利用层次分析法、回归分析法建立粉丝数的估算模型,运用Lingo、Matlab等软件得出最终粉丝数的定量估算结果,粉丝数即与新闻观看者等同。最后,将模型结果与实际相结合,对模型进行优化改进后,提出新的决策方案,以提高估算的精确度,使结果更加合理。 相似文献
57.
58.
刘瑛 《重庆理工大学学报(自然科学版)》2006,20(7):192-194
许多大学生学习英语的动力局限于考试、升学、就业,实际上,除此以外,英语学习可以使大学生树立远大的理想,培养良好的道德,激发创造的潜能,只有这些才可以增强大学生学习英语的持久学习动力。英语里蕴藏的文化借鉴是增强英语学习动力的有效手段。 相似文献
59.
基于模糊神经网络的感应加热电源温度控制 总被引:1,自引:0,他引:1
通过对原有感应加热电源温度控制方法的分析,提出了一种适合于非线性系统基于模糊神经网络的温度控制方法,并介绍了该系统的组成及实现方法。 相似文献
60.
Summary. A numerical simulation is performed to investigate the viscous flow over a smooth wavy wall undergoing transverse motion in the form of a streamwise travelling wave, which is similar to the backbone undulation of swimming fish. The objective of this study is to elucidate hydrodynamic features of the flow structure over the travelling wavy wall and to get physical insights to the understanding of fish-like swimming mechanisms in terms of drag reduction and optimal propulsive efficiency. The effect of phase speed, amplitude and Reynolds number on the flow structure over the wavy wall, the drag force acting on the wall, and the power consumption required for the propulsive motion of the wall is investigated. The phase speed and the amplitude, which are two important parameters in this problem, predicted based on the optimal propulsive efficiency agree well with the available data obtained for the wave-like swimming motion of live fish in nature. 相似文献